A previously unreported differential diagnosis of the complex regional pain syndrome.

For 3 years, a female patient (67 years old, 157 cm, 64 kg) suffered from burning pain in her right ankle and foot. In the course of her disease, she consulted her general practitioner, a dermatologist, internist, angiologist, neurologist, and vascular and orthopedic surgeons. Diagnostic evaluation included a variety of probable causes, e.g., rheumatic disease, chronic venous insufficiency, thrombophlebitis, neuropathy, and Achilles tendinitis; pain however persisted. Based on the clinical presentation with neuropathic pain, swelling and discoloration and on a X-ray showing a local rarefication of the bone, an orthopedist diagnosed complex regional pain syndrome (CRPS) and referred her to our pain clinic. Upon presentation to us, her current pain medication consisted of 300 mg of gabapentin, twice daily. She had previously been treated with different non-steroidal anti-inflammatory drugs. Calcitonine nose spray was recommended once, but never administered.